Is ACTN2 p.Arg328Gln (c.983G>A) pathogenic?

ACTN2 p.Arg328Gln (c.983G>A) is classified Conflicting classifications of pathogenicity in ACTN2 (ClinVar, Conflicting submitters, 6 submitters; last evaluated 2026-01-13). AlphaMissense: likely benign (0.1618); Very rare (popmax 0.00267%, afr); Associated with myopathy, congenital, with structured cores and z-line abnormalities.

What condition is associated with ACTN2 p.Arg328Gln (c.983G>A)?

ACTN2 p.Arg328Gln (c.983G>A) is associated with myopathy, congenital, with structured cores and z-line abnormalities, dilated cardiomyopathy 1AA, familial hypertrophic cardiomyopathy (ClinVar).

How common is ACTN2 p.Arg328Gln (c.983G>A) in the general population?

ACTN2 p.Arg328Gln (c.983G>A) is very rare (popmax 0.00267%, afr) (gnomAD).

What do computational predictors say about ACTN2 p.Arg328Gln (c.983G>A)?

AlphaMissense predicts likely benign (score 0.1618) — an in-silico prediction, not a clinical call.

ACTN2 p.Arg328Gln

c.983G>A · rs774046373 · VCV296503

Conflicting classifications of pathogenicity Conflicting submitters

Classification

Conflicting classifications of pathogenicity

ClinVar

Review

Conflicting submitters ★☆☆☆

ClinVar · 6 submitters

AlphaMissense

likely benign

0.1618 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 0.00267%, afr)

Missense predictors

0/2 damaging

AlphaMissense, SaProt · REVEL no call

Conditions

myopathy, congenital, with structured cores and z-line abnormalities

Computational evidence

Protein change
AlphaMissense	0.1618	likely benign
REVEL	0.366	indeterminate
SaProt	LLR -9.46	tolerated
⇒ AlphaMissense and SaProt both call this tolerated; REVEL makes no call.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 12	GERP 2.2, phastCons 1
Regional constraint	o/e 0.90	unconstrained · MANE · 25 kb · p 0.0054 · regional, not allelic
Overall
CADD	32.0	PHRED · no single calibrated threshold — expert panels disagree

AlphaMissense carries the ACMG weight for missense; REVEL and SaProt are independent agreement signals.

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.00267% African / African-American · 2/74,860 alleles

Filtering AF 0.000763% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.000605%

Overall 0.00112% 18/1,613,928 alleles · very rare

Ancestry group	Frequency	1 in
African / African-Americangrpmax	0.00267%	37,430
Admixed American	0.00167%	59,986
European (non-Finnish)	0.00127%	78,670

Rarity supports pathogenicity (ACMG PM2); frequency above a disease-specific BA1/BS1 threshold argues against it. A variant frequent in one ancestry group can be near-absent in others, so a single global figure can mislead.

Variant & gene context

Gene: ACTN2
Protein: p.Arg328Gln
Coding: c.983G>A
MANE Select: NM_001103
dbSNP: rs774046373
Type: single nucleotide variant
Location: chr1:236739408 (GRCh38)
Gene constraint: LOEUF 0.432 · pLI 1.00 (gnomAD)
Structure: AlphaFold pLDDT 84.88 · 18 PDB
Residue 328: an α-helix

Full ACTN2 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

myopathy, congenital, with structured cores and z-line abnormalities — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Also linked: dilated cardiomyopathy 1AA familial hypertrophic cardiomyopathy myopathy, distal, 6, adult-onset, autosomal dominant

Similar variants

ACTN2 p.Arg328Trp Conflicting classifications of pathogenicity ★ ⚠ same residue
ACTN2 p.Arg328= Likely benign ★ same residue
ACTN2 p.Ala119Thr Pathogenic/Likely pathogenic ★★ same condition
ACTN2 p.Leu727Arg Pathogenic/Likely pathogenic ★★ same condition
ACTN2 p.Thr247Met Likely pathogenic ★★ same condition
ACTN2 c.1107+3G>A Uncertain significance ★★ same condition
ACTN2 c.1108-10A>G Uncertain significance ★★ same condition
ACTN2 c.1255+1G>C Uncertain significance ★★ same condition

Built on 18 open, versioned datasets — ClinVar, gnomAD, AlphaMissense, REVEL, ClinGen & more — plus Sugi Variant's own cross-source analysis. Source data 2026-01–2026-10, ClinVar 2026-10. Full sources & versions →

Cite Sugi Variant

Gür T. Sugi Variant: A Deterministic Per-Variant Germline Reference from a Knowledge Graph for Humans and AI Agents. 2026. doi:10.5281/zenodo.21509445. This variant: https://sugi.bio/variant/actn2-p-arg328gln (accessed [today's date]).

Preprint & method: sugi.bio/variant/method Machine-readable: this page as Markdown